This invention relates to a wrapped cylindrical bush having an obliquely extending oil groove or grooves on its outer peripheral surface.
Heretofore, oil grooves for introduction of lubricating oil into a bearing are formed by machining in a bearing housing into which a wrapped cylindrical bush is securely force fitted.
Since such bearing housing is generally large in size and complicated in structure, it is very hard to form such oil grooves by machining, so that highly complicated and expensive machine tools are required.
In conventional bearings of the type, lubricating oil is supplied to other portions of a wrapped cylindrical bush through an oil groove or grooves on an inner peripheral surface of a bearing housing, such as by oil holes in a wrapped cylindrical bush, through an oil groove or grooves on an inner peripheral surface of the bush and into a gap (namely, oil film clearance) between the inner peripheral surface of the bush and a rotary shaft. When lubricating oil is supplied through oil holes in the bush, into the oil groove or grooves on the inner peripheral surface of the bush and into the oil film clearance in this manner, problems are caused in that control of the supply of lubricating oil is disadvantageously influenced by the rotating movement of the rotary shaft and the variation of the oil film clearance or needed quantity of lubricating oil is not effectively supplied to the other portions of the wrapped cylindrical bush.
As will become apparent from the drawings, the grooves are in communication only with the outer peripheral surface of the bush. As will be further apparent from the drawings, the term "in communication with only the outer peripheral surface of the bush" is intended to include embodiments wherein the grooves extend up to and "communicate" with the edge of the bush. The term "in communication with only the outer peripheral surface of the bush" merely means that there are no openings in the grooves which extend through the bush to the inner peripheral surface thereof or which communicate with any other passage or reservoir between the outer and inner peripheral surfaces of the bush.